Method fob pbeventing and removing



Fatented July 15, 1952 METHOD FOR PREVENTING AND REMOVING ACCUMULATIONS OF FOREIGN MATE- RIALS Noble 0. Smith, Larkspur, Caliii; Frank J'. Keaton, special administrator of said Noble 0. Smith, deceased, assignor to Yosemite Chemical Co.

i No Drawing. Application November 7, 1947,

Serial No. 784,759

7 Claims. (C1. 134--4) This invention relates to a method for preventing and removing rust, scale, dirt, marine growth, etc. from various surfaces and more particularly to a method which utilizes emulsifying agents for such purposes. 7 s I 'The present method has been specifically designed to overcome many of the difficulties which have been inherent in processes disclosed in the prior art. These difliculties may be divided into two general classes,,one concerned with the problem of application of the preventative or remover and the other with the problem of insuring that all foreign material is completely removed.

: With regard to insuring removalof all foreign material, the prior art has generally depended upon a dissolving action of one'kind or another by means of which th foreign material is broken down, either physically or chemically, so that it may beeasily carried away. But basically, these methods have'in common the requirement that the bond between the surface to be cleaned and the foreign material must be either dissolved or chemically changed. The present method appears not to be dependent upon this phenomenon, but rather relies on the swellingcharacteristic of an emulsion or gel to mechanically break the foreign material from the surface- In other Words, the emulsifying agent causes theformation of agel between the surface and the foreign material and its inherent expansion mechanically loosens the latter. An emulsifying agent of opposite characteristics may'then be applied to reduce the gel and cause the foreign material adhering to itto drop 0155.

The above discussion has been primarily conoerned with how the present invention actually operates. The second important aspect is the method herein disclosed for applying the emulsifying agents. Although the agents could,'of course, be applied by painting, washing, spraying or other conventional methods, these are not the most satisfactory methods for use on large enclosed areas. For example, in a marine drydock, very large compartments are utilized to raise-and sink the clock by a process of filling and emptying the same. -These are usually filled fromthe bottom with sea water and as a consequence, the present invention utilizes an agent which will float upon the water and is thus carriel up and down on the waters surface, coating the sides of the compartment as the water level rises and falls. It is to be noted that the agents are not interspersed or mixed throughout the volume of the water, but form alayer atits surface; and also are not eliminated when the compartment is emptied. The agents floatingon a shallow layer of water are left behind.

So far, the discussion has been concerned prinf cipally with the use of the process for cleaning or removal. The same principle may also be conveniently utilized as a preventative method.- In view of the fact that an emulsion is an excellent barrier against the penetration of gases.

watervapor, and other substances which tend to cause the formation of rust, scale, foreign material, etc., an agent of the type. described above and with somewhat lesseremulsifying characteristics can be left permanently in the enclosed compartments, such as those described above, with excellent results. Thus. if the com-- partment is new or has already been cleaned,

the provision of a layer of the agents on-the water surface will effectively prevent the deposit of rust, scale and other foreign matter.,

- Although; as has been stated, the agents hereindescribed'maybe applied in any convenient fashion, the process will be described herein as it is used in one of its primary applications, i, e., inmarine dry-docks. T l" I ,As iswelliknowii, marine dry docks aregeem: prised of one or more flotation compartments,

alternately filled and emptied to permit subme'r sions and liftings of the dock. The surrounding water is, of course, used in this processl and repetitions of the filling and emptying procedure causes considerable amounts of 'rust'and scale to form and the deposit of appreciableamounts of dirt and other foreign matter. Normally,'dry

docks areinade of metal and these various dc}.

posits" and the reaction with, the metal aremost undesirable to insure'long life of the dock;

In the present. instance, the process will be first describedin"conjunctionwith a dry dock which has been in use for sometime and whose compartments show considerable evidence of rust, scale and the deposit of foreign material; The removal of thismaterial ma be accomplished by first adding to each submersible com-' partment an emulsifying agent which herein will be called agent No. '1. Agent No. l isone which will cause. the formation of a water-in-oilemulsion and is added while the .drydock israised andthe water 'levelin the compartments is at Suificient of agent'No. lisi the. lowest point; addel to form a layerv of. from on {the surface of the water.

As has been stated, agent No. 1 produces a water-in-oil emulsion and may comprisegone of the fatty: acid or other organic, acid soaps of a divalent metal suchas calc1um, baris one which 3 ium, strontium, etc. Of course, it should be one which does not chemically react with metal, wood, etc. or other materials contained in or comprising the compartment. It also should preferably have high penetrating or polar characteristics which will cause the oil to displace water from the metal surface and from between the particles of rust, scale, etc. Although a heavy oil would be best as a diluent, diesel or stove oil is quite satisfactory. Thus, an"accept able example of agent No. 1 might comprise parts (by weight) of a calcium soap, such as calcium lanolate, 2 to 3 parts pine'oil andlilojpartsi diesel oil.

After agent No. 1 is added'to the'compartment, the water is permitted to flow into the; compartment. as by normal sinking of the deck.,

As the level of the water rises, agent No. 1.will be deposited on the walls, bracing, etc. of the compartment as each area is successively submerged. The agenthas a high penetratingcharacteristic and after one or more, submersions, it will have'been foundto haveworked itsway into all cracks, spaces, blisters, and particularly in, through and behind the deposits'of rust, scale and foreign matter. To insure better penetration and the coating of all areas, the dock may be rocked, if -desired, but; this is not always necessary; i

In practice; after agent No. 1 has beenadded, itfis preferably left alone for from 2 to 6 days, during which time thedockwill presumably be' raised and lowered several times. In any event, agent'No. 1' soon begins-to forman extremely rigid; water-in-oil emulsion orgel wherever it has-been deposited; This viscous emulsion-or gel (which terms are; used interchangeably herein) has extremely stable qualities andis generally of the consistency of Vaseline and will not, flow dii-a'vertical surface: It'i'orms not only onsolid surfaces. but also'tends to. form a solid, jelly-like mfas son the water surface. i

Of course, during the formation oithegel, it exhibits its normal tendency to swell iandtwhere deposited under or behind'rust, scale or other foreign deposits, forces them to itself by adhesionLi far. as is. determinable; 'i't is-this mechanical f phenomenon alone which causes the breaking away of the foreign material andfit '-is not believed that any particular chemicalreaction between; the gel' and' the foreign material takes place' Naturally, too, through" repeated submersions, additionatlayers of' the emulsion aredepo'sitedfiand each swelling i'n turn causes a further separation between the surfaces to be: cleaned and the foreign material;

"After the rigid emulsion or gelihas completely formed and, brokenaway the foreign material; agent'No. 2 is added to thecompartments, Agent No. 2'must be of such composition'that itjhas a tendencyto breakdown the already formedwaterin-oiiemulsion' and, must'be oil soluble. Such materials asthe phenols or-sodium sulphonate of highmolecular, weight-have been found 'fextremelysatisfactory, for example, a satisfactory agent No. 2 would comprise ,Sparts (by weight) sodium sulphonate, 10 parts phenol and IQOv parts, diesel oil. Agent No. 2 isjalso preferably added when. the waterv level is low and 'subsequent'submersions of the dock cause it, like agentNo'. 1, tov be deposited on all of the' areas on which thewateriii-oil emulsion has formed.

" Agent-No. 2 immediately begins to breakdown orreduce thewater-in -oil emulsion: The gelst'ructure is" disrupted at -least' sumciently that is the gel will drop or flow off the vertical surfaces carrying the foreign material with it. It is to be noted that agent No. 2 is added, depending upon its specific characteristics, in suflicient quantity to make the gel less viscous, but not sufliciently to reduce or invert the emulsion into an oil-in-water emulsion. In normal dry dock operation it may take from 4 to 5 days before the reduction process is complete. Its obvious pur- I pose. is to reduce the viscosity so that gravity flow and subsequent submersions are enabled to carry away the rust, scale and other foreign material which have been broken away from thesurfaces and which adhered to the gell.

Thus,-in the new process, the gel is first formed to break. the foreign material from the surfaces to becleaned and it is then reduced to permit the material to drop off or be carried away by subsequent submersions.

The method outlined above is obviously most satisfactory where the cleaning is to be'done on surfaces in a closed container or: system in which there is a periodic flow of liquid on which the agents may be floated. As has already been said, the same results may-be accomplished by applying the-agents and thenecessary water by submersion, spraying, painting or other conventio'nal methods. However, it is obvious that in: those. instances where aperiodic flow of the. system is present, the specific method described insures excellent and complete 'coatings ofall surfaces-with aminimum of time and expense. Even in closed systems-where no periodic-flow is-had, such a:- method of flotation may: well be utilized if dismantlingof the system would be. necessary. to accomplish the coating.

Obviously, agents having-stronger or lesser tendenciesto form and reduce'the gel may-require different periods of time. The timefor any given agentsmay be determined byobseryation, agent No. 2 being added when agent No. l' has formed theiviscous gel described above. The process islcompleted, after the addition of agent No. 2: when the gelhaslargely broken down, at: which time itwill be found that the: cleaned. areasare coated with: a. thin,.. white, creamy emulsion. i

' Inthe above. description, it was assumed-that the surfaces concerned wereoriginally covered with rust, scale, etc., making a cleaning operation. necessary. The. use of both of the, aboveagentswas therefore-necessary. However, once the surfaces have been-cleaned, as by theabove method or. otherwise, or. if the. surfaces arev new,-

, they. may. be maintained in such condition by the use of: agent No.1 alone or. by: asingle. 8p: plication ofa combination of agentsNos. l1 and 2 This: preventiye. feature of the invention de-- pendsupon the fact that an emulsion is an ex cellent barrier against gases, water vapor, etc. which cause rust and the adherence of other foreign material. Thus, if the-surfacesto be protected are periodically coated with agent No. 1- or-combination of'agents-Nos. 1 andz (eitherby conventionalmethods, or bythe process-described above in' conjunction with adrydock)-, to' fo'rm' the 'water-in oilemulsion, thesurfaces will be thoroughlyand permanently protectedagainstformationor deposit of-foreign materials:

" The main distinction betweenthetreatmentaccorded 'fthe surfacesin the cleaning process and iri the preventive processis the-elimination of -ftheyuse ofor separate application ofagent No.-

Agent N o; 2---is required -in --the cleaning process -to breakdown or reduce the rigid emu] sion or gel formed by rather large amounts of agent No. 1. If this were not used, the gel formed on the water surface would be so thick that additional coatings would not be added by subsequent immersions and the material removed would remain adhering to the gel on the surfaces. a

As a consequence, for reventive purposes, the necessary proportions of agents Nos. 1 and 2 could be added at the same time, or a weakened agent No. 1 could be used. For example, if the formula given above for agent No. 1 included considerably more of the calcium soap, the tendency to create a viscous emulsion or gel is greatly lessened, which is desirable in the preventive process. However, such dilution also cuts down on the protective characteristics aiforded by the soap and it might then be necessary to add other waxes, asphalt, tars or heavy petroleum oils to increase the preventive characteristics. For this reason, it is more practical to use some of both agents Nos. 1 and 2, the combination of which, acting as a single agent, has the required emulsii'ying and preventive characteristics, and the desired white creamy emulsion is formed on the surfaces.

This creamy emulsion serves to adequately coat and protect the surfaces against the formation and deposit of foreign materials, and is of the same consistency as is produced finally in the removing process. In practice, of course, small amounts of the diluted agent No. 1 or the combination of agents Nos. 1 and 2 will be added from time to time as required in order to maintain said emulsion at all times.

I claim:

1. The process for removing material such as rust. scale and the like from a metal surface comprising the steps of: filling the interstices in said material and between said material and said surface with an emulsifying agent in oil, said agent comprising a fatty acid soap of a divalent metal automatically adapted to and capable of forming with water a water-in-oil viscous gel emulsion adapted to expand during its formation; providing the water to the agent so filling said interstices; permitting the formation of said gel emulsion in said interstices whereby its expansion during said formation will tend to loosen said material from said surface; thinning said gel with an oil soluble thinner capable of reducing the viscosity of the gel to facilitate its removal from said surface together with the material so loosened from said surface.

2. In the process for removing rust, scale, and the like from a metal surface on which any of such materials has formed that comprises the steps of: coating said surface with an emulsifying agent in oil and in the presence of Water, said emulsifying agent being an organic soap of .a divalent metal, said agent in oil thereafter automatically forming a water-in-oil emulsion and viscous gel on said surface after its application thereto in the presence of water; and thereafter reducing the viscosity of said viscous gel by applying an oil soluble thinner thereto after it has formed, said thinner being capable of reducing the viscosity of the already formed emulsion thereby causing said material to freely flow on said surface.

3. The process of removing material such as rust, scale and the like that is attached to metal on which it is formed from the surface of said metal comprising the steps of depositing between said material and said surface a fluid containing an organic soap of a divalent metal, said,

fluid having the property of forming an expansible, water-in-oil emulsion in the presence of water and providing the water for the formation 5 of said emulsion whereby the expansion'ofthe latter between said material and said surface will force the material from saidv surface, and thereafter reducing the viscosity of said emulsion by applying an oil soluble thinner thereto, said lothinner being capable of reducing the viscosity of the already formed emulsion thereby causing said material and thinned emulsion to fall therefrom. 4. The process of removing material such as rust, scale and the like from a surface to which it is attached that comprises the steps of floating on a body of water an emulsifying agent in oil and which agent in oil has the characteristic ,7 of forming in association with said water a 201 water-in-oil emulsion and relatively viscous gel, 'said agent being an organic soap of a divalent "metal, immersing such surface and material in said water below said agent and before the forming of said water-in-oil emulsion and then withdrawing said surface and said material through said agent whereby water and said agent in oil will be adhered to said surface and will enter any interstices in said material and between such material and said surface and will form said water-in-oil emulsion on said surface and in said interstices, then permitting the said formation of said water-in-oil emulsion in said interstices and on said surface, and thereafter substantially thinning the said emulsion with an oil soluble thinner, said thinner being capable of causing said emulsion and any of the said material therein to fall away from said surface.

5. The process for removing material such as rust and scale from the metal side walls of a container that comprises the steps of: providing a body of water against said walls, floating an emulsifying agent in oil on the surface of said body and in contact with said walls, said emulsifying agent being an organic soap of a divalent metal having the characteristic of adhering to said walls together with water upon raising and lowering the level of said body and of forming a water-in-oil emulsion with said water after it has so adhered to said walls, raising and lowering the level of said body to cause said adherence and coating of said walls and the said formation of said emulsion on said walls, said emulsion having the further characteristic of being expansible during its formation whereby its said expansion between the metal surface of said walls and any of said material will force said material from said walls and into the emulsion coating said walls, then reducing the viscosity of said emulsion by applying an oil soluble agent thereto, said agent being capable of reducing the viscosity of said emulsion so that the emulsion and any of said material will fall from said walls.

6. The process for removing rust, scale, and other foreign material attached to a metal surface therefrom comprising the steps of: coating the metal to be cleaned with an oil containing a penetrating and emulsifying agent in the presence of water having the property of entering any of the interstices in the rust. scale, etc., and forming an expanding viscous gel emulsion therein, said emulsifying agent having a fatty acid soap of a divalent metal selected from the group consisting of calcium, barium, strontium and in the ratio of about 5 parts by weight of said calcium soap to about 2 to 3 parts byweight amazes:

7,- df' pine oil: and, about; 100; parts by; weightmf;

petroleum oil, contacting the so coatedmetal with water so. as; to permit. said emulsifyinglagent said oil andinthe presence of vwatertq term-.521 d" expanding viscous gel engulsiondn said;injzerstjges;,

and .ubetween the metal surface; andzsaid ush scale and foreignsmaterial so .the lathe will 81 611 containingsaid agent, said emulslfyingugent bemgzzannrga imsoap;of a divalent metal, applyingnwa tento said coated surface to eflect the formationof said waterAn-oil emulsionand subsequently reconizactin saidv c ated su e'wi water-.1707 maintainipsaidi water-in-oil emulsion.

NOBLE C. SMITH.

REFERENCES. CITED Thefollowing=references-are of record in the file of this patent:

UNITEDTSTATES .PA'IENTS Date Number Name v 767,575.;- Le- B1a-ne Aug. 16, 1904 1 5655236 Wandel n Dec. 15, 1925 1,850,700: Taylor Mar. 22, 1932 2,936,};48 Amthor Apr. 7, 1936 2,136,681. Eultonl -Nov. 15,,1938 2;;28364 Frager, v Oct. 7, 1947 2342400 Sh walter v May '25, 1948 

3. THE PROCESS OF REMOVING MATERIAL SUCH AS RUST, SCALE AND THE LIKE THAT IS ATTACHED TO METAL ON WHICH IT IS FORMED FROM THE SURFACE OF SAID METAL COMPRISING THE STEPS OF: DEPOSITING BETWEEN SAID MATERIAL AND SAID SURFACE A FLUID CONTAINING AN ORGANIC SOAP OF A DIVALENT METAL, SAID FLUID HAVING THE PROPETY OF FORMING AND EXPANSIBLE WATER-IN-OIL EMULSION IN THE PRESENCE OF WATER AND PROVIDING THE WATER FOR THE FORMATION OF SAID EMULSION WHEREBY THE EXPANSION OF THE LATTER BETWEEN SAID MATERIAL AND SAID SURFACE WILL FORCE THE MATERIAL FROM SAID SURFACE, AND THEREAFTER REDUCING THE VISCOSITY OF SAID EMULSION Y APPLYING AN OIL SOLUBLE THINNER THERETO, SAID THINNER BEING CAPABLE OF REDUCING THEREBY THE VISCOSITY OF THE ALREADY FORMED EMULSION THEREBY CAUSING SAID MATERIAL AND THINNED EMULSION TO FALL THEREFROM. 